Splitting out the Audio library.

sdk/lib/html/scripts/systemhtml.py

Index: sdk/lib/html/scripts/systemhtml.py
diff --git a/sdk/lib/html/scripts/systemhtml.py b/sdk/lib/html/scripts/systemhtml.py
index 9bb8186ba9337b07fa5e299d20fb71734b12ffa9..db68bee518c0a27d57b633eee18cd4b89242fb97 100644
--- a/sdk/lib/html/scripts/systemhtml.py
+++ b/sdk/lib/html/scripts/systemhtml.py
@@ -202,7 +202,8 @@ _svg_element_constructors = {
 
 _element_constructors = {
   'html': _html_element_constructors,
-  'svg': _svg_element_constructors
+  'svg': _svg_element_constructors,
+  'web_audio': {},
 }
 
 _factory_ctr_strings = {
@@ -214,6 +215,10 @@ _factory_ctr_strings = {
     'provider_name': '_SvgElementFactoryProvider',
     'constructor_name': 'createSvgElement_tag',
   },
+  'web_audio': {
+    'provider_name': 'document',
+    'constructor_name': '$dom_createElement'
+  },
 }
 
 def ElementConstructorInfos(typename, element_constructors,
@@ -981,8 +986,10 @@ class DartLibrary():
 class DartLibraries():
   def __init__(self, template_loader, library_type, output_dir):
     self._libraries = {
-      'svg': DartLibrary('svg', template_loader, library_type, output_dir),
       'html': DartLibrary('html', template_loader, library_type, output_dir),
+      'svg': DartLibrary('svg', template_loader, library_type, output_dir),
+      'web_audio': DartLibrary('web_audio', template_loader, library_type,
+          output_dir),
     }
 
   def AddFile(self, basename, library_name, path):